Trisazo dyes for inks for ink jet printing

ABSTRACT

A process for printing an image on a substrate including applying thereto a composition comprising a liquid medium and a tris-azo compound of Formula (1) or salt thereof: 
                         
wherein:
     A is an optionally substituted alkenyl, homocyclic or heterocyclic group;   L 1  and L 2  are each independently optionally substituted aryl or heteroaryl; and   m and n are each independently 0 or 1 such that m+n is 1 or 2;
 
wherein:
       (i) the compound of Formula (1) is optionally in the form of a metal chelate; and   (ii) at least one of L 1  and L 2  carries at least one substituent selected from sulpho, carboxy, C 1-4 -alkoxy and C 1-4 -alkoxy-OH. Also claimed are compositions and compounds comprising Formula (1).

This invention relates to compounds, to processes for their preparation,to compositions derived therefrom and to their use in ink jet printing(“IJP”). IJP is a non-impact printing technique in which droplets of inkare ejected through a fine nozzle onto a substrate without bringing thenozzle into contact with the substrate.

There are many demanding performance requirements for dyes and inks usedin IJP. For example they desirably provide sharp, non-feathered imageshaving good water-fastness, light-fastness and optical density. The inksare often required to dry quickly when applied to a substrate to preventsmudging, but they should not form a crust over the tip of ink jetnozzles because this will stop the printer from working. The inks shouldalso be stable to storage over time without decomposing or forming aprecipitate which could block the fine nozzles.

JP 58-174459 describes certain dis-azo dyes comprising once-coupled1,8-dihydroxynaphthalene and their use in ink jet printing.

JP 57-36693 and U.S. Pat. No. 4,395,288 describe certain tetra-azo dyescomprising 1,8-dihydroxynaphthalene and their use in ink jet printing.

U.S. Pat. No. 1,209,154, published in 1916, describes the synthesis ofcertain tris-azo dyes comprising a 1,8-dihydroxynaphthalene group at oneend and a 1,3-diaminobenzene group at the other end. These dyes are usedfor the conventional dyeing of cotton.

GB 809279, published in 1959, describes the synthesis of coppercomplexes of certain tris-azo dyes comprising once-coupled1,8-dihydroxynaphthalene and a 3,3′-dimethoxy-1,1′-diphenyl linker.These dyes are used for the conventional dyeing of cotton.

Surprisingly it has been found that the tris-azo dyes of the presentinvention have exceptional properties when used as ink jet inks,producing prints of high optical density (OD) of a neutral black withexcellent light and ozone-fastness and high operability.

According to the present invention there is provided a process forprinting an image on a substrate comprising applying thereto acomposition comprising a liquid medium and a tris-azo compound ofFormula (1) or salt thereof:

wherein:

-   A is an optionally substituted alkenyl, a homocyclic or heterocyclic    group;-   L¹ and L² are each independently optionally substituted aryl or    heteroaryl; and-   m and n are each independently 0 or 1 such that m+n is 1 or 2;    wherein:    -   (i) the compound of Formula (1) is optionally in the form of a        metal chelate; and    -   (ii) at least one of L¹ and L² carries at least one substituent        selected from sulpho, carboxy, C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH.

Preferably the composition is applied to the substrate by means of anink jet printer. The ink jet printer preferably applies the compositionto the substrate in the form of droplets which are ejected through asmall orifice onto the substrate. Preferred ink jet printers arepiezoelectric ink jet printers and thermal ink jet printers. In thermalink jet printers, programmed pulses of heat are applied to thecomposition in a reservoir by means of a resistor adjacent to theorifice, thereby causing the composition to be ejected in the form ofsmall droplets directed towards the substrate during relative movementbetween the substrate and the orifice. In piezoelectric ink jet printersthe oscillation of a small crystal causes ejection of the compositionfrom the orifice.

The image is preferably text, a picture, a photorealistic image or acombination thereof.

The substrate is preferably paper, plastic, metal or glass, morepreferably a treated substrate such as a coated paper or coated plastic,especially plain paper. One of the advantages of the present process isits ability to provide very good printing results even on plain paper.

Preferred papers have an acid, alkaline or neutral character. Examplesof commercially available treated papers include HP Premium CoatedPaper™, HP Photopaper™, HP Printing paper™ (available from HewlettPackard Inc.); Stylus Pro 720 dpi Coated Paper™, Epson Photo QualityGlossy Film™, Epson Photo Quality Glossy Paper™(all available from SeikoEpson Corp.); Canon HR 101 High Resolution Paper™, Canon GP 201 GlossyPaper™, Canon HG 101and HG201 High Gloss Film™, Canon PR101™ (allavailable from Canon); Kodak Premium Photopaper, Kodak PremiumInkJetpaper™ (available from Kodak); Konica Inkjet Paper QP™Professional Photo Glossy, Konica Inkjet Paper QP™ Professional Photo2-sided Glossy, Konica Inkjet Paper QP™ Premium Photo Glossy, KonicaInkjet Paper QP™ Premium Photo Silky™ (available from Konica) and XeroxAcid Paper (available from Xerox).

In this specification any groups shown in the free acid form alsoinclude the salt form. Furthermore the formulae shown in thisspecification cover all tautomers thereof.

When the compound of Formula (1) is in the form of a salt preferredsalts are alkali metal salts, especially lithium, sodium and potassiumsalts, ammonium and substituted ammonium salts and mixtures thereof.Especially preferred salts are salts with ammonia and volatile amines.The free acid form may be converted into a salt using known techniques.For example, an alkali metal salt may be converted into a salt withammonia or an amine by dissolving an alkali metal salt of thecomposition in water, acidifying with a mineral acid and adjusting thepH of the solution to pH 9 to 9.5 with ammonia or the amine and removingthe alkali metal cations by dialysis.

The preferred optionally substituted homocyclic or heterocyclic groupgroups represented by A are optionally substituted aryl, heteroaryl andnon-aromatic cyclic groups.

Preferred optionally substituted aryl groups represented by A, L¹ and L²are each independently optionally substituted phenyl, biphenyl ornaphthyl. In another embodiment of the present invention it is preferredthat A is optionally substituted heteroaryl. Preferred optionallysubstituted heteroaryl groups represented by A, L¹ and L² are anyheterocycle or substituted heterocycle comprising a 5- to 7-memberedring. Similarly preferred non-aromatic heterocyclic groups representedby A comprise a 5- to 7-membered ring, preferably comprising at leastone double bond.

Examples of heteroaryl groups include pyridyl, furyl, thienyl,thiazolyl, isothiazolyl, imidazolyl, benzimidazolyl, pyrazinyl,pyrimidyl, quinolyl, isoquinolyl, benzofuryl, benzothienyl, pyrazolyl,indolyl, purinyl, isoxazolyl, oxazolyl, thiadiazolyl and furazanylgroups.

Examples of non-aromatic cyclic groups include pyridonyl, pyrazolonyl,piperidinyl, piperazinyl, pyrrolidinyl, morpholinyl, tetrahydrofuranyl,tetrahydrothiophenyl and tetrahydropyranyl, with pyridonyl beingespecially preferred.

Preferred optionally substituted alkenyl groups are of the Formula (2)and tautomers thereof:

wherein:

-   -   Y is an electron withdrawing group;    -   Y¹ is H, alkyl, aryl, OR or N(R)₂ in which each R independently        is H, optionally substituted alkyl or optionally substituted        aryl; and    -   X¹ comprises at least one heteroatom selected from N, O and S.

Y is preferably selected from CN, CO₂H, CO₂R, CON(R)₂, COR and —SO₂N(R)₂in which each R independently is as defined above. When R is optionallysubstituted alkyl it is preferably C₁₋₈-alkyl, more preferablyC₁₋₄-alkyl. When R is optionally substituted aryl it is preferablyphenyl or naphthyl, more preferably phenyl. When R is optionallysubstituted alkyl or aryl optional substituents are preferably selectedfrom water solubilising groups, particularly SO₃H, SO₂NH₂, CO₂H or PO₃H₂and salts thereof.

When Y¹ is alkyl it is preferably C₁₋₈alkyl, more preferably C₁₋₄-alkyl.When Y¹ is aryl it is preferably phenyl.

X¹ is preferably OR, CO₂R or NR in which R is as defined above.

More preferably Y is CO₂R¹, Y¹ is OR¹ and X¹ is OR¹ wherein each R¹independently is H or C₁₋₄-alkyl.

Optional substituents which may be present on A, L¹ and L² arepreferably selected from OH, SO₃H, CN, carbonamido, PO₃H₂, CO₂H, NO₂,NH₂, optionally substituted alkyl (especially C₁₋₄-alkyl optionallycarrying a sulpho, carboxy, phosphato, C₁₋₄-alkoxy, amino or hydroxygroup), optionally substituted alkoxy (especially C₁₋₄-alkoxy optionallycarrying a sulpho, carboxy, phosphato, C₁₋₄-alkoxy, C₁₋₄-alkyl, amino orhydroxy group), optionally substituted aryl (especially phenyl or phenylcarrying from 1 to 3 substituents selected from sulpho, carboxy,phosphato, C₁₋₄-alkoxy, amino, hydroxy and N carrying one or twoC₁₋₄-alkyl groups optionally carrying a sulpho, carboxy, phosphato,C₁₋₄-alkoxy, amino or hydroxy group), optionally substituted amine(especially N carrying one or two C₁₋₄-alkyl groups optionally carryinga sulpho, carboxy, phosphato, C₁₋₄-alkoxy, amino or hydroxy group) andoptionally substituted acylamine (especially C₁₋₄-acylamino).

Preferably A carries from 0 to 5 substituents, more preferably 1 to 4substituents, especially 1, 2 or 3 substituents. In a preferredembodiment A is not 1,3-diaminophenyl.

As examples of optionally substituted phenyl and naphthyl groupsrepresented by A there may be mentioned 2,4-dihydroxyphenyl,3-sulfo-4,6-diaminophenyl, 2-hydroxy-4-diethylaminophenyl2-sulfo-4-diethylaminophenyl, 1-hydroxy-3,6-disulphonaphthyl and1,8-dihydroxy-3,6-disulfonaphthyl. Preferred optionally substitutedheteroaryl groups represented by A are any heterocycle or substitutedheterocycle comprising a 5- to 7-membered ring, more preferablyoptionally substituted pyridyl, pyrazolyl or 1,2,4-triazolyl.

Preferably L¹ and L² are each independently, or comprise, one or morearylene groups, more preferably one or two optionally substitutedphenylene or naphthylene groups. When L¹ or L² is, or comprises, morethan one arylene group, the said arylene groups are optionally connectedby means of a covalent bond or group containing from 1 to 10 atomsselected from O, S, N, C, H and combinations thereof, for example —O—,—NR²—, —NR²—CO—, —NR²CONR²—, —S—, —SO—, —SO₂—, —SO₂NR²— or —C R²═C R²—,wherein each R² independently is H or C₁₋₄-alkyl.

Preferably L¹ and L² are each independently optionally substitutedphenylene or naphthylene, wherein at least one of L¹ and L² carries atleast one substituent selected from sulpho, carboxy, C₁₋₄-alkoxy andC₁₋₄-alkoxy-OH. Preferably L¹ and L² each independently carries from 0to 3 substituents, more preferably 1 or 2 substituents, such that atleast one of L¹ and L² carries at least one substituent selected fromsulpho and carboxy. Further preferably at least one of L¹ and L² carriesat least one substituent selected from C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH

Preferably L¹ carries a substituent selected from sulpho and carboxy.

Preferably L² carries at least one substituent selected from sulpho,carboxy C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH.

As examples of optionally substituted phenylene and naphthylene groupsrepresented by L¹ and L² there may be mentioned 2-sulphophenylene,2-carboxyphenylene, 2,5-dihydroxyethyloxyphenylene,2,5-dimethoxyphenylene, 2,5-disulphophenylene, 2,5-diethoxyphenylene,2-methyl-5-methoxyphenylene and 7-sulphonaphthylene.

When the compound of Formula (1) is in the form of a metal chelate themetal is preferably Boron or a transition metal, more preferably Mn, Fe,Cr, Co, Ni, Cu or Zn, especially Co, Ni or Cu. The metal may becomplexed with the compound of Formula (1) in a ratio of from 1:2 to2:1, preferably in a ratio of metal to compound of Formula (1) of 1:2,2:3, 1:1, 2:2 or 2:1, especially 2:1. However we have found that whenthe compound of Formula (1) is not in the form of a metal chelate thecompound is still a valuable colorant for ink jet printing. Suchunmetallised dyes are cheaper and easier to make than the correspondingmetal chelates and they are more environmentally friendly due to theabsence of, for example, transition metals.

Preferably the compound of Formula (1) is black.

Bearing in mind the above preferences, the compound of Formula (1) ispreferably of the Formula (1) wherein:

-   A is optionally substituted pyridyl, furyl, thienyl, thiazolyl,    isothiazolyl, imidazolyl, benzimidazolyl, pyrazinyl, pyrimidyl,    quinolyl, isoquinolyl, benzofuryl, benzothienyl, pyrazolyl, indolyl,    purinyl, isoxazolyl, oxazolyl, thiadiazolyl, furazanyl, pyridonyl,    pyrazolonyl, piperidinyl, piperazinyl, pyrrolidinyl, morpholinyl,    tetrahydrofuranyl, tetrahydrothiophenyl or tetrahydropyranyl;-   L¹ phenyl or naphthyl optionally carrying a substituent selected    from sulpho and carboxy;-   L² is phenyl or naphthyl carrying at least one substituent selected    from sulpho, carboxy, C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH; and-   m and n are each independently 0 or 1 such that m+n is 1 or 2;    wherein said optional substituents are selected from OH; SO₃H; CN;    carbonamido; PO₃H₂; CO₂H; NO₂; NH₂; C₁₋₄-alkyl optionally carrying a    sulpho, carboxy, phosphato, C₁₋₄-alkoxy, amino or hydroxy group;    C₁₋₄-alkoxy optionally carrying a sulpho, carboxy, phosphato,    C₁₋₄-alkoxy, C₁₋₄-alkyl, amino or hydroxy group; phenyl or phenyl    carrying from 1 to 3 substituents selected from sulpho, carboxy,    phosphato, C₁₋₄-alkoxy, amino, hydroxy and N carrying one or two    C₁₋₄-alkyl groups optionally carrying a sulpho, carboxy, phosphato,    C₁₋₄-alkoxy, amino or hydroxy group; N carrying one or two    C₁₋₄-alkyl groups optionally carrying a sulpho, carboxy, phosphato,    C₁₋₄-alkoxy, amino or hydroxy group; and C₁₋₄-acylamino.

Further preferably, bearing in mind the above preferences, the compoundof Formula (1) is of the Formula (1) wherein:

-   A is pyridonyl carrying at least one substituent selected from    carbonamido and C₁₋₄ alkyl;-   L¹ is phenyl carrying at least one sulpho substituent;-   L² is phenyl carrying al least one substituent selected from sulpho,    carboxy C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH; and-   m and n are both 1.

According to a second aspect of the present invention there is provideda tris-azo compound of Formula (1) or salt thereof as hereinbeforedefined, with the provisos that:

-   -   (i) the compound of Formula (1) is optionally in the form of a        metal chelate;    -   (ii) L¹ and L² are each independently optionally substituted        phenylene or naphthylene;    -   (iii) optional substituents present on L¹ and L² are selected        from OH, SO₃H, CN, carbonamido, PO₃H₂, CO₂H, NO₂, NH₂,        optionally substituted alkyl, optionally substituted alkoxy,        optionally substituted aryl, optionally substituted amine and        optionally substituted acylamine;    -   (iv) at least one of L¹ and L² carries at least one substituent        selected from sulpho, carboxy, C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH;        and    -   (v) when L¹ carries a methoxy group A is not 1,3-diaminophenyl.

The preferences for the compound according to the second aspect of thepresent invention are as described above in relation to the first aspectof the present invention, with the proviso that when both groupsrepresented by L are free from sulpho, carboxy and C₁₋₄-alkoxy-OH groupsthen A is not 1,3-diaminophenyl.

According to a third aspect of the present invention there is provided acomposition comprising a tris-azo compound of Formula (1) or saltthereof as defined in relation to the first aspect of the presentinvention and a low melting point solid or a liquid medium comprisingwater and an organic solvent, wherein the compound of Formula (1) is notFormula (3) or a salt thereof:

Preferably the group represented by A in the compound of Formula (1) isnot 1,3-diaminophenyl.

The composition preferably comprises:

-   -   (a) from 0.01 to 30 parts of a compound of Formula (1) or salt        thereof as defined in relation to the first aspect of the        present invention; and    -   (b) from 70 to 99.99 parts of a low melting point solid or a        liquid medium comprising water and an organic solvent;        wherein all parts are by weight and the number of parts of        (a)+(b)=100.

The process preferably uses the aforementioned composition.

The number of parts of component (a) is preferably from 0.1 to 20, morepreferably from 0.5 to 15, and especially from 1 to 5 parts. The numberof parts of component (b) is preferably from 99.9 to 80, more preferablyfrom 99.5 to 85, especially from 99 to 95 parts.

Preferably component (a) is completely dissolved in component (b).Preferably component (a) has a solubility in component (b) at 20° C. ofat least 10%. This allows the preparation of liquid dye concentrateswhich may be used to prepare inks and reduces the chance of the dyeprecipitating if evaporation of the liquid medium occurs during storage.

The weight ratio of water to organic solvent is preferably from 99:1 to1:99, more preferably from 99:1 to 50:50 and especially from 95:5 to80:20.

It is preferred that the organic solvent present in the mixture of waterand organic solvent is a water-miscible organic solvent or a mixture ofsuch solvents. Preferred water-miscible organic solvents includeC₁₋₆-alkanols, preferably methanol, ethanol, n-propanol, isopropanol,n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol andcyclohexanol; linear amides, preferably dimethylformamide ordimethylacetamide; ketones and ketone-alcohols, preferably acetone,methyl ether ketone, cyclohexanone and diacetone alcohol; water-miscibleethers, preferably tetrahydrofuran and dioxane; diols, preferably diolshaving from 2 to 12 carbon atoms, for example pentane-1,5-diol, ethyleneglycol, propylene glycol, butylene glycol, pentylene glycol, hexyleneglycol and thiodiglycol and oligo- and poly-alkyleneglycols, preferablydiethylene glycol, triethylene glycol, polyethylene glycol andpolypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol;mono-C₁₋₄-alkyl ethers of diols, preferably mono-C₁₋₄-alkyl ethers ofdiols having 2 to 12 carbon atoms, especially 2-methoxyethanol,2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol,2-[2-(2-methoxyethoxy)ethoxy]ethanol,2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol and ethyleneglycol monoallylether;cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone,N-ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; cyclicesters, preferably caprolactone; sulphoxides, preferably dimethylsulphoxide and sulpholane. Preferably the liquid medium comprises waterand 2 or more, especially from 2 to 8, water-soluble organic solvents.

Especially preferred water-soluble organic solvents are cyclic amides,especially 2-pyrrolidone, N-methyl-pyrrolidone and N-ethyl-pyrrolidone;diols, especially 1,5-pentane diol, ethyleneglycol, thiodiglycol,diethyleneglycol and triethyleneglycol; and mono-C₁₋₄-alkyl andC₁₋₄-alkyl ethers of diols, more preferably mono-C₁₋₄-alkyl ethers ofdiols having 2 to 12 carbon atoms, especially((2-methoxy-2)-ethoxy)-2-ethoxyethanol.

Optionally the liquid medium comprises an oxidant.

Preferred low melting point solids have a melting point in the rangefrom 60° C. to 125° C. Suitable low melting point solids include longchain fatty acids or alcohols, preferably those with C₁₈₋₂₄ chains, andsulphonamides. The compound of Formula (1) may be dissolved in the lowmelting point solid or may-be finely dispersed in it.

Typically the liquid medium will further comprise one or moresurfactants, for example anionic and/or nonionic surfactants. Examplesof anionic surfactants include: Sulfonate surfactants such asSulfosuccinates (Aerosol™ OT, A196; AY and GP, available from CYTEC) andSulfonates (Aerosol™ DPOS-45, OS available from CYTEC; Witconate™ C-50Havailable from WITCO; Dowfax™ 8390 available from DOW); and Fluorosurfactants (Fluorad™ FC99C available from 3M). Examples of nonionicsurfactants include: Fluoro surfactants (Fluorad™ FC170C available from3M); Alkoxylate surfactants (Tergitol™ series 15S-5, 15S-7, and 15S-9available from Union Carbide); and Organosilicone surfactants (Silwet™L-77 and L-76-9 available from WITCO).

One or more buffers may optionally be included in the liquid medium tomodulate pH of the ink. The buffers can be organic-based biologicalbuffers or inorganic buffers, preferably, organic-based. Examples ofpreferably-employed buffers include tris(hydroxymethyl)aminomethane(TRIS), available from companies such as Aldrich Chemical (Milwaukee,Wis.), 4-morpholine ethanesulfonic acid (MES),4-morpholinepropanesulfonic acid (MOPS), andbeta-hydroxy-4-morpholinepropanesulfonic acid (MOPSO). Further, thebuffers employed should provide a pH ranging from about 3 to about 9 inthe practice of the invention, preferably about 4 to about 6 and mostpreferably from about 4 to about 5.

One or more of the biocides commonly employed in inkjet inks mayoptionally be used in the ink, such as Nuosept™ 95, available from HulsAmerica (Piscataway, N.J.); Proxel™ GXL, available from Zeneca(Wilmington, Del.); and glutaraldehyde, available from Union CarbideCompany (Bound Brook, N.J.) under the trade designation Ucarcide 250.

Inks according to the invention may optionally also include one or moremetal chelator. Such chelators are used to bind transition metal cationsthat may be present in the ink. Examples of preferred metal chelatorsinclude: ethylenediaminetetraacetic acid (“EDTA”),diethylenediaminepentaacetic acid (“DPTA”),trans-1,2-diaminocyclohexanetetraacetic acid (“CDTA”),ethylenedinitrilotetraacetic acid (“EGTA”), or other chelators.

In one embodiment inks according to the invention have a pH of fromabout 3 to about 5, preferably from about 3.5 to about 4.5. In anotherembodiment the pH of the composition is preferably from 4 to 11, morepreferably from 7 to 10. Optionally the composition comprises a buffer.

The viscosity of the composition at 25° C. is preferably less than 50cP, more preferably less than 20 cP and especially less than 5 cP.

When the compositions according to the invention are used as ink jetprinting compositions, the composition preferably has a concentration ofless than 500 parts per million, more preferably less than 100 parts permillion of halide ions. It is especially preferred that the compositionhas less than 100, more preferably less than 50 parts per million ofdivalent and trivalent metals, wherein parts refer to parts by weightrelative to the total weight of the composition. We have found thatpurifying the compositions to reduce the concentration of theseundesirable ions reduces nozzle blockage in ink jet printing heads,particularly in thermal ink jet printers. Similarly low levels asdivalent and trivalent metals are also preferred.

The compounds of the invention may be used as the sole colorant in thecompositions because of their attractive black shade. However, ifdesired, one may combine the present compounds together and/or with oneor more further colorants to reduce nozzle blockage (by improving theirsolubility) or if a slightly different shade is required for aparticular end use. The further colorants are preferably dyes. Whenfurther colorants are included in the composition these are preferablyselected from black, magenta, cyan and yellow colorants and combinationsthereof.

Suitable further black colorants include C.I.Food Black 2, C.I.DirectBlack 19, C.I.Reactive Black 31, PRO-JET™ Fast Black 2, C.I.Direct Black195; C.I.Direct Black 168; and black dyes described in patents byLexmark (e.g. EP 0 539,178 A2, Example 1, 2, 3, 4 and 5), OrientChemicals (e.g. EP 0 347 803 A2, pages 5-6, azo dyes 3, 4, 5, 6, 7, 8,12, 13, 14, 15 and 16) and Seiko Epson Corporation.

Suitable further magenta colorants include PRO-JET™ Fast Magenta 2 .

Suitable further yellow colorants include C.I.Direct Yellow 142;C.I.Direct Yellow 132; C.I.Direct Yellow 86; PRO-JET™ Yellow OAM;PRO-JET™ Fast Yellow 2; C.I.Direct Yellow 85; C.I. Direct Yellow 173;and C.I.Acid Yellow 23.

Suitable further cyan colorants include phthalocyanine colorants, C.I.Direct Blue 199 and C.I. Acid Blue 99.

The composition may also contain additional components conventionallyused in ink jet printing inks, for example viscosity and surface tensionmodifiers, corrosion inhibitors, biocides, kogation reducing additivesand surfactants which may be ionic or non-ionic.

In a fourth aspect of the invention we have also devised a process forthe preparation of a compound of Formula (1) as hereinbefore definedwhich comprises diazotising an amine of Formula (4) and coupling theresultant diazonium salt with a compound of Formula A-H:

The compound of Formula (4) may be prepared by diazotising a compound ofFormula CH₃CONH-L¹-N═N-L²-NH₂ and coupling the resultant diazonium saltonto a suitable 1,8-dihydroxy naphthalene compound, then removing theCH₃CO group by hydrolysis. The compound of Formula CH₃CONH-L¹-N═N-L²-NH₂may be prepared by diazotising an amine of formula CH₃CONH-L¹-NH₂ andcoupling onto an amine of Formula H-L²-NH₂.

Preferably the diazotisations are carried out using a diazotising agent,especially sodium nitrite under acidic conditions. Further preferablythe diazotisations are carried out at a temperature of 0 to 5° C. In theabove process A, L¹, L², m and n are as hereinbefore defined.

A further aspect of the present invention provides a paper, an overheadprojector slide or a textile material printed with a composition, acompound or by means of a process according to the present invention.

A still further as aspect of the present invention provides an ink jetprinter cartridge, optionally refillable, comprising one or morechambers and a composition, wherein the composition is present in atleast one of the chambers and the composition is as defined in the thirdaspect of the present invention.

The present compounds and compositions provide prints of attractive,neutral black shades that are particularly well suited for the ink jetprinting of text and images. The compositions have good storagestability and low tendency to block the very fine nozzles used in inkjet printers. Furthermore, the resultant images have good opticaldensity, light-fastness, wet-fastness and resistance to fading in thepresence of oxidising air pollutants (e.g. ozone).

The invention is further illustrated by the following Examples in whichall parts and percentages are by weight unless specified otherwise. Theabbreviation “Ac” means CH₃CO—.

EXAMPLE 1 Preparation of

Preparation of Intermediate 2,5-di-(2-acetoxyethoxy)aniline Step1—Preparation of 1,4-bis-(2-acetoxyethoxy)hydroquinone

Hydroquinonebis-(2-hydroxyethyl)ether (179 g), acetic acid (100 ml) andacetic anhydride (300 ml) were stirred and heated under refluxovernight. After cooling to room temperature and drowning into water (2l) the product was isolated by filtration, washed with water, dried andrecrystallised from ethanol to give 212 g of product.

Step 2—Preparation of 2-Nitro-1,4-bis-(2-acetoxyethoxy)hydroquinone

The product of step 1 (211.5 g) was dissolved in acetic acid (1800 ml).A mixture of nitric acid (51.9 ml) and acetic acid (200 ml) was thenadded over 20 minutes keeping the temperature below 20° C. Afterstirring at room temperature overnight the solution was drowned intowater (9 l) and the product isolated by filtration, washed with waterand recrystallised from ethanol to give 209 g of product.

Step 3—Preparation of 2,5-di-(2-acetoxyethoxy)aniline

2-Nitro-1,4-bis-(2-acetoxyethoxy)hydroquinone (115 g) was dissolved inethanol at 50° C. and reduced with hydrogen in the presence of palladiumcatalyst (2 g, 5% Pd/C). When uptake of hydrogen ceased the solution wasscreened to remove the catalyst and the filtrates allowed to cool toroom temperature. The crystalline solid was isolated by filtration anddried under vacuum to give 90 g of product.

Stage one—Preparation ofmonoazo-4-(4-Acetylamino-2-sulpho-3-phenylazo)-2,5-di-(2-acetoxyethoxy)aniline

4-Amino-3-sulphoacetanilide (174 g; 0.6 mol) was stirred in water (2.5l) at pH 9 and sodium nitrite (45.54 g; 0.66 mol) added. The solutionwas added to ice/water containing concentrated hydrochloric acid (180ml) with stirring. After stirring for 1.5 h at less than 10° C. theexcess nitrous acid was destroyed by the addition of sulphamic acid.2,5-di-(2-acetoxyethoxy)aniline (178.2 g; 0.6 mol) was dissolved inacetone (1000 ml) and added to the above diazonium salt suspension at0-10° C. followed by the slow addition of pyridine (30 ml). Afterstirring overnight at room temperature the precipitated product wasfiltered-off, washed with water. The damp paste was then stirred inacetone, filtered and dried (50° C.) to give a an orange solid (210 g;64%).

Stage Two—Preparation of Bisazo Intermediate

The monoazo product from Stage one (24.75 g; 0.05 mol) was dissolved inwater (300 ml) with stirring at pH 10 to which sodium nitrite ( 6.90 g;0.1 mol ) and acetone (200 ml) were added. The resulting mixture wasthen added to 0.10M hydrochloric acid (70 ml) with stirring at roomtemperature. After stirring for 1 h, the excess nitrous acid wasdestroyed by the addition of sulphamic acid. The resulting diazoniumsalt was then added to a stirred solution of chromotropic acid (20.00 g;0.05 mol) at 0-10° C. at pH 7-8 maintained by the addition of 2N lithiumhydroxide when necessary. After stirring overnight the product wasprecipitated by the addition of 25% (w/v) lithium chloride then filteredand washed with 30% (w/v) lithium chloride solution. The resulting damppaste was suspended in water (700 ml) and lithium hydroxide hydrate(25.00 g; 0.60 mol) added and the solution heated at 70° C. After 3 hthe solution neutralised to pH 6-7 by the addition of concentratedhydrochloric acid. The product was precipitated by the slow addition of20% (w/v) lithium chloride, filtered and washed with 25% (w/v) lithiumchloride solution. The damp paste was dissolved in water and thendialysed to low conductivity. The solution was evaporated to dryness(70° C.) to give a black powder (25.5 g; 67%)

Stage Three—Preparation of Title Dye

The amino disazo compound from Stage Two (12.00 g; 0.0158 mol) wasdissolved in water (250 ml) with stirring at pH 9 to which calsolene oil(1 ml) and sodium nitrite (1.20 g; 0.0174 mol) was added. The resultingsolution was then added to ice/water (100 g) containing concentratedhydrochloric acid (5 ml) with stirring at 0-10° C. . After stirring for1 h at 0-10° C. the excess nitrous acid was destroyed by the addition ofsulphamic acid. The resulting diazonium salt was added to a stirredsolution of 1-(4-sulphophenyl)-3-carboxy-5-pyrazolone (5.39 g; 0.19 mol)in water (100 ml) at 0-10° C. and then adjusted to pH 7. After stirringovernight the solution was poured into acetone (3 l) with stirring,filtered and washed with acetone. The solid dissolved in water anddialysed to low conductivity to give after evaporation (80° C.) a blackpowder (11.61 g; 68.8%; γ_(max) 612 nm and an ε_(max) of 82232; massspectrum (M-H)-ve 1037).

EXAMPLE 2 Preparation of

The method of Example 1 was repeated except that in place of4-amino-3-sulpho acetanilide there was used4-amino-3-carboxyacetanilide. The resultant compound had a γ_(max) at602 nm and an ε_(max) of 79,227.

EXAMPLE 3 Preparation of

The method of Example 2 was repeated except that in place of2,5-di-(2-acetoxyethoxy)aniline there was used 2,5-di-(methoxy)aniline.The resultant compound had a γ_(max) at 601 nm.

EXAMPLE 4 Preparation of

The method of Example 1 was repeated except that in place of2,5-di-(2-acetoxyethoxy)aniline there was used1-amino-7-sulphonaphthalene. The resultant compound had a γ_(max) at 604nm and an ε_(max) of 69,419.

EXAMPLES 5 to 38

Examples 5 to 38 shown in Table 1 were prepared by following the generalmethod of Example 1, except that (with reference to Table 1) in place of1-(4-sulphophenyl)-3-carboxy-5-pyrazolone there was used the compoundshown in Column A, in place of 4-Amino-3-sulphoacetanilide there wasused the compound shown in Column L¹ and in place of2,5-di-(2-acetoxyethoxy)aniline there was used the compound shown incolumn L², unless otherwise indicated (“N/A”) in each case. The finaldye structure is shown for each example in Table 1.

TABLE 1 λ_(max) Ex A L¹ L² Final dye structure ε_(max) (nm) 5

N/A N/A

72925 604 6

N/A N/A

73364 604 7

N/A N/A

87995 618 8

N/A N/A

81232 601 9

N/A N/A

61463 611 10

N/A N/A

82378 612 11

N/A N/A

81414 609 12

N/A N/A

81685 600 13

N/A N/A

99865 626 14

N/A N/A

85064 612 15

N/A N/A

75,785 610 16

N/A

608 17

N/A

617 18

N/A N/A

609 19

N/A N/A

608 20

N/A N/A

21

N/A N/A

22

N/A

591 23

607 24

N/A

599 25

604 26

N/A

599 27

N/A

608 28

607 29

594 30

611 31

N/A

641 32

N/A

608 33

N/A N/A

601 34

613 35

N/A N/A

607 36

N/A N/A

604 37

602 38

N/A

627

EXAMPLE 39 Preparation of

Stage 1 Preparation of the Mono-Azo Intermediate

4-Amino-3-sulpho acetanilide diazonium salt (0.2 mol), prepared as inExample 1 (stage 1) above, was added to a stirred solution ofchromotropic acid (80.0 g; 0.2 mol) in water (400 ml) at 0-10° C. and pH6-7 maintained by addition of 2N lithium hydroxide when necessary. Afterstirring overnight lithium hydroxide hydrate (80 g; 2 mol) was added andthe solution was heated at 70-80° C. for 4 hours. The solution wascooled to room temperature, then adjusted to pH 3 by the addition ofconcentrated hydrochloric acid. The solution was then poured intoacetone and then the liquors decanted off. The resulting oil wasdissolved in water at pH 8 to give 796.0 g of a 0.1827 molar solution ofthe above mono-azo intermediate.

Stage 2 Preparation of the Dis-Azo Intermediate

Sodium nitrite (1.52 g; 0.022 mol ) was added to the stirred solutionfrom stage 1 (100 ml, 0.02 mol ) which was then added dropwise toice/water (100 ml) containing concentrated hydrochloric acid (6 ml).After stirring for 2 hours the excess nitrous acid was destroyed by theaddition of sulphamic acid. The resulting diazonium salt was added to astirred solution of 1-hydroxy-3-sulpho-7-aminonaphthalene (5.96 g; 0.022mol) in water (50 ml) at 0-10° C. and pH 8-9 maintained by the additionof 2N lithium hydroxide when necessary. After stirring overnight theproduct was precipitated by the addition of acetone, filtered and washedwith acetone to give after drying a black solid (30.5 g: 0.02 mol).

Stage 3 Preparation of Title Dye

The product from stage 2 (0.01 mol) was dissolved in water (150 ml) atpH 9,sodium nitrite (0.77 g: 0.011 mol) added. The resulting suspensionwas added to ice/water (100 g) containing concentrated hydrochloric acid(6 ml) at 0-10° C. After stirring for 2 hours the excess nitrous acidwas destroyed by the addition of sulphamic acid. The resulting diazoniumsalt was added to a stirred solution of1-ethyl-6-hydroxy-4-methyl-2-oxo-1,2-dihydropyridine-3-carboxamide (2.45g; 0.0125 mol) in water (25 ml) at 0-10° C. and pH 9-10 maintained bythe addition of 2N lithium hydroxide when necessary. After stirringovernight the product was precipitated by the addition of acetone thenfiltered and washed to give after drying a black solid (1.01 g; 10%;γ_(max) 598 nm, 631 nm (M-3H)-ve 324).

EXAMPLES 40 to 44

Examples 40 to 44 shown in Table 2 were prepared by following thegeneral method of Example 39, except that (with reference to Table 2) inplace of1-ethyl-6-hydroxy-4-methyl-2-oxo-1,2-dihydropyridine-3-carboxamide therewas used the compound shown in Column A, in place of gamma acid therewas used the amine shown in Column L¹ and in place of 4-amino-3-sulphoacetanilide there was used the amine shown in column L². The final dyestructure is shown for each example in Table 2.

TABLE 2 λ_(max) Ex A L¹ L² Final dye structure ε_(max) (nm) 40

83444 611 41

77567 655 42

85240 666 43

576 44

582

EXAMPLE 45 Preparation of

Stage 1 Preparation of the Mono-Azo Intermediate

4-Amino-3-sulpho acetanilide diazonium salt (0.1 mol) prepared asExample 1 (stage 1) was added to a stirred solution of1-hydroxy-6-amino-3,5-naphthalenedisulphonic acid (35.09 g; 0.11 mol) at0-10° C. and pH 9-10 maintained by the addition of 2N lithium hydroxidewhen necessary. After stirring overnight the solution was adjusted to pH8, the product was precipitated by the addition of 30% (w/v) lithiumchloride, then filtered and washed with 40% (w/v) lithium chloridesolution. The resulting solid was dissolved in water at pH 10 to give688.7 g of a solution of 0.085 mol of the mono-azo intermediate above.

Stage 2 Preparation of Dis-Azo Intermediate

Sodium nitrite (6.3 g; 0.091 mol) was added to the stirred solution fromstage 1 (0.084 mol) which was then added to ice/water (200 g) containingconcentrated hydrochloric acid (40 ml) at 0-10° C. After stirring for1.5 hours the excess nitrous acid was destroyed by the addition ofsulphamic acid. The resulting diazonium salt was then added to a stirredsolution of chromotropic acid (36.96 g; 0.092 mol) at 0-10 ° C. at pH7-8 maintained by addition of 2N lithium hydroxide when necessary. Afterstirring overnight the product was precipitated by the addition of 30%(w/v) lithium chloride and then filtered and washed with 35% (w/v)lithium chloride solution. The resulting damp paste was dissolved inwater to give 1150 ml of a solution containing 0.084 mol of the dis-azointermediate above.

Stage 3 Preparation of Hydrolysed Dis-Azo Intermediate

Lithium hydroxide hydrate (50 g; 1.24 mol) was added to 1000 ml of thestirred solution from stage 2 (0.073 mol), which was then heated at70-80° C. for 2.5 hours. The solution was adjusted to pH 9 withconcentrated hydrochloric acid and then cooled overnight to give 1279.0g of a solution containing 0.072 mol of the dis-azo intermediate above.

Stage 4 Preparation of Title Compound

Sodium nitrite (0.84 g; 0.012 mol) was added to 165 ml of the stirredsolution from stage 3 (0.01 mol) which was then added dropwise toice/water (100 g) containing concentrated hydrochloric acid (6 ml) at0-10° C. After stirring for 2 hours the excess nitrous acid wasdestroyed by the addition of sulphamic acid. The resulting diazoniumsalt was then added dropwise to a stirred solution of1-ethyl-6-hydroxy-4-methyl-2-oxo-1,2-dihydropyridine-3-carboxamide (2.40g; 0.012 mol) in water (100 ml) at 0-10° C. and pH 5-7 maintained by theaddition of 2N lithium hydroxide solution when necessary. After stirringovernight the product was precipitated by the addition of 15% (w/v)lithium chloride, then filtered and washed with 20% (w/v) lithiumchloride solution. The damp paste was dissolved in water (400 ml) anddiluted with acetone (4000 ml) with stirring then filtered and washedwith acetone. The solid was dissolved in water and then dialysed to lowconductivity to give, after evaporation to dryness (60° C.), a blackpowder (8.15 g; 75%; γ_(max) 588 nm, ε_(max) 132812; mass spectrum(M-2H)-ve 527).

EXAMPLES 46 to 59 Mixtures

The following mixtures described in Table 3 may be prepared in which thebracketed number is the number of parts by weight of the relevantcompound:

TABLE 3 Example Compound (parts) Compound (parts) 46 Example 8 (1)Example 1 (0.9) 47 Example 4 (1) C.I. Direct Yellow 132 (0.1) 48 Example8 (1) Example 13 (0.5) 49 Example 15 (1) Example 14 (1) 50 Example 8 (1)C.I. Direct Blue 199 (0.15) 51 Example 1 (1) Example 8 (1) 52 Example 8(1) Pro-Jet ™ Fast Black 2 (0.7) 53 Example 12 (1) Example 14 (0.5) 54Example 8 (1) C.I. Direct Yellow 86 (0.12) 55 Example 3 (1) Example 8(0.5) 56 Example 8 (1) Pro-jet ™ Yellow OAM (0.05) 57 Example 1 (1)Example 4 (1) 58 Example 4 (1) Pro-Jet ™ Fast Yellow 2 (0.05) 59 Example1 (1) Pro-Jet ™ Fast Magenta 2 (0.05)

EXAMPLE 60 Ink Formulations

Inks may be prepared according to the following formulation wherein Dyeis the compound or mixture from each of the above Examples above:

2-Pyrrolidone  5 parts Thiodiglycol  5 parts Surfynol ™ 465  1 part(from Air Products Inc., U.S.A.) Dye  3 parts Water  86 parts

Further inks described in Tables 4 and 5 may be prepared wherein the Dyedescribed in the first column is the compound or mixture made in theabove Example of the same number. Numbers quoted in the second columnonwards refer to the number of parts of the relevant ingredient and allparts are by weight. The inks may be applied to paper by thermal orpiezo ink jet printing.

The following abbreviations are used in Table 4 and 5:

PG=propylene glycol

DEG=diethylene glycol

NMP=N-methyl pyrollidone

DMK=dimethylketone

IPA=isopropanol

MEOH=methanol

2P=2-pyrollidone

MIBK=methylisobutyl ketone

P12=propane-1,2-diol

BDL=butane-2,3-diol

CET=Tris(2-aminoethyl)amine buffer

PHO=Na₂HPO₄ and

TBT=tertiary butanol

TDG=thiodiglycol

TABLE 4 Dye Na Dye Content Water PG DEG NMP DMK NaOH Stearate IPA MEOH2P MIBK 1 2.0 80 5 6 4 5 2 3.0 90 5 5 0.2 3 10.0 85 3 3 3 5 1 4 2.1 91 81 5 3.1 86 5 0.2 4 5 6 1.1 81 9 0.5 0.5 9 7 2.5 60 4 15 3 3 6 10 5 4 8 565 20 10 9 2.4 75 5 4 5 6 5 10 4.1 80 3 5 2 10 0.3 11 3.2 65 5 4 6 5 4 65 12 5.1 96 4 13 10.8 90 5 5 14 10.0 80 2 6 2 5 1 4 15 1.8 80 5 15 162.6 84 11 5 17 3.3 80 2 10 2 6 18 12.0 90 7 0.3 3 19 5.4 69 2 20 2 1 3 320 6.0 91 4 5

TABLE 5 Dye Dye Content Water PG DEG NMP CET TBT TDG BDL PHO 2P PI2 213.0 80 15 0.2 5 22 9.0 90 5 1.2 5 23 1.5 85 5 5 0.15 5.0 0.2 24 2.5 90 64 0.12 25 3.1 82 4 8 0.3 6 8 0.9 85 10 5 0.2 8 8.0 90 5 5 0.3 8 4.0 7010 4 1 4 11 8 2.2 75 4 10 3 2 6 8 10.0 91 6 3 8 9.0 76 9 7 3.0 0.95 5 85.0 78 5 11 6 8 5.4 86 7 7 8 2.1 70 5 5 5 0.1 0.2 0.1 5 0.1 5 8 2.0 9010 8 2 88 10 8 5 78 5 12 5 8 8 70 2 8 15 5 8 10 80 8 12 8 10 80 10

EXAMPLES 61-66 Print Test Examples

The inks described in the first paragraph of Example 60 were ink-jetprinted onto a variety of papers using a Hewlett Packard DeskJet 560C™.The CIE colour co-ordinates of each print (a, b, L, Chroma and hue H)were measured using a Gretag Spectrolino Spectrodensitometer™ with0°/45° measuring geometry with a spectral range of 400-700 nm at 20 nmspectral intervals, using illuminant D50 with a 2° (CIE 1931) observerangle and a density operation of status A. No less than 2 measurementswere taken diagonally across a solid colour block on the print with asize greater than 10 mm×10 mm. The properties of the resultant printsare shown in Table 6, where the example number of the dye used toprepare the ink is indicated in the left hand column, and ROD isRelative Optical Density. The substrates mentioned in Tables 6, 7 and 8were as follows:

Number HP Printing Paper ™ 1 HP Premium Plus MkII ™ 2 Epson PremiumPhoto ™ 3 IIford Instant Dry ™ 4

TABLE 6 Ex. No. Dye Substrate ROD L a b C H 61 1 1 1.97 11 −1 −14 14 26561 1 2 1.20 31 −3 −12 13 257 61 1 3 2.02 10 −1 −15 15 264 61 1 4 2.08 91 −18 18 274 62 4 1 1.73 16 4 −18 19 282 62 4 2 1.03 37 0 −9 9 269 62 43 1.91 12 4 −20 21 282 62 4 4 1.71 16 2 −16 16 277 63 7 1 1.93 13 7 −3131 284 63 7 2 1.18 33 −1 −22 22 268 63 7 3 1.96 13 9 −32 33 285 63 7 41.98 13 11 −36 37 286 64 16 1 1.82 14 −2 −11 11 259 64 16 2 1.17 32 −2−11 11 259 64 16 3 2.07 9 −2 −13 13 261 64 16 4 2.01 10 −1 −15 15 266 6522 1 1.95 10 1 −8 8 275 65 22 2 1.19 31 1 −9 9 275 65 22 3 2.16 7 2 −1010 281 65 22 4 2.20 6 4 −12 12 288 66 23 1 1.92 11 8 −15 17 298 66 23 21.22 30 3 −14 14 281 66 23 3 2.15 6 10 −14 17 306 66 23 4 2.15 7 13 −2024 304Light Fastness

To evaluate light fastness the prints were irradiated in an Atlas Ci5000Weatherometer™ for 100 hours. The results are shown in Table 7 where theexample number of the dye used to prepare the ink is indicated in theleft hand column. The degree of fade is expressed as ΔE where a lowerfigure indicates higher light fastness, and ΔE is defined as the overallchange in the CIE colour co-ordinates L, a, b of the print and isexpressed by the equationΔE=(ΔL ² +Δa ² +Δb ²)^(0.5).

TABLE 7 Example Dye number number SUBSTRATE ΔE 61 1 1 12 61 1 2 9 61 1 33 61 1 4 9 62 4 1 8 62 4 2 14 62 4 3 5 62 4 4 22 63 7 1 12 63 7 2 13 637 3 5 63 7 4 10 64 16 1 16 64 16 2 9 64 16 3 9 64 16 4 22 65 22 1 14 6522 2 11 65 22 3 6 65 22 4 9 66 23 1 7 66 23 2 10 66 23 3 9 66 23 4 4Ozone Fastness

The inks from Examples 61 to 66 were printed onto the substrate shownusing a HP₅₆₀™ ink jet printer. The printed substrate was then assessedfor ozone stability using an ozone test cabinet from Hampden TestEquipment. The test was carried out for 24 hours at 40° C. and 50%relative humidity in the presence of 1 part per million of ozone.Fastness of the printed ink to ozone was judged by the difference in theoptical density before and after exposed to ozone using a GretagSpectrolino Spectrodensitometer. Thus, the lower the % OD loss thegreater the ozone fastness. The results are shown in Table 8 where theexample number of the dye used to prepare the ink is indicated in theleft hand column. These clearly demonstrate that inks based oncompositions of this invention display good ozone fastness.

TABLE 8 Example Dye % ROD number number SUBSTRATE loss 61 1 3 15 61 1 419 62 4 3 12 62 4 4 16 63 7 3 20 63 7 4 23 64 16 3 24 64 16 4 31 65 22 310 65 22 4 7 66 23 3 4 66 23 4 −1

1. A process for printing an image on a substrate comprising applyingthereto by means of an ink-jet printer a composition comprising a liquidmedium and a tris-azo compound of Formula (1) or salt thereof:

wherein: A is an alkenyl, homocyclic or heterocyclic group; L¹ and L²are each independently aryl or heteroaryl; and m and n are eachindependently 0 or 1 such that m+n is 1 or 2; wherein: (i) the compoundof Formula (1) is not in the form of a metal chelate; and (ii) at leastone of L¹ and L² carries at least one substituent selected from sulpho,carboxy, C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH.
 2. A process according to claim1 wherein the image is text, a picture, a photorealistic image or acombination thereof.
 3. A process according to claim 1 wherein thesubstrate is paper, plastic, metal or glass.
 4. A process according toclaim 1 wherein: A is optionally substituted pyridyl, furyl, thienyl,thiazolyl, isothiazolyl, imidazolyl, benzimidazolyl, pyrazinyl,pyrimidyl, quinolyl, isoquinolyl, benzofuryl, benzothienyl, pyrazolyl,indolyl, purinyl, isoxazolyl, oxazolyl, thiadiazolyl, furazanyl,pyridonyl, pyrazolonyl, pipendinyl, piperazinyl, pyrrolidinyl,morpholinyl, tetrahydrofuranyl, tetrahydrothiophenyl ortetrahydropyranyl; L¹ phenyl or naphthyl optionally carrying asubstituent selected from sulpho and carboxy; L² is phenyl or naphthylcarrying at least one substituent selected from sulpho, carboxyC₁₋₄-alkoxy and C₁₋₄-alkoxy-OH; and m and n are each independently 0 or1 such that m+n is 1 or 2; wherein said optional substituents areselected from OH; SO₃H; CN; carbonamido; PO₃H₂; CO₂H; NO₂; NH₂;unsubstituted C₁₋₄-alkyl or substituted C₁₋₄-alkyl carrying a sulpho,carboxy, phosphato, C₁₋₄-alkoxy, amino or hydroxy group; unsubstitutedC₁₋₄-alkoxy or substituted C₁₋₄-alkoxy carrying a sulpho, carboxy,phosphato, C₁₋₄-alkoxy, C₁₋₄-alkyl, amino or hydroxy group; phenyl orphenyl carrying from 1 to 3 substituents selected from sulpho, carboxy,phosphato, C₁₋₄-alkoxy, amino, hydroxy and N carrying one or twounsubstituted C₁₋₄-alkyl groups or substituted C₁₋₄-alkyl groupscarrying a sulpho, carboxy, phosphato, C₁₋₄-alkoxy, amino or hydroxygroup; N carrying one or two unsubstituted C₁₋₄-alkyl groups orsubstituted C₁₋₄-alkyl groups carrying a sulpho, carboxy, phosphato,C₁₋₄-alkoxy, amino or hydroxy group; and C₁₋₄-acylamino.
 5. A tris-azocompound of Formula (1) or salt thereof:

wherein: A is an optionally substituted pyridonyl group; m and n areeach independently 0 or 1 such that m+n is 1 or 2; and with the provisosthat: (i) the compound of Formula (1) is not in the form of a metalchelate; (ii) L¹ and L² are each independently optionally substitutedphenylene or naphthylene; (iii) the optional substituents present on L¹and L² are selected from OH, SO₃H, CN, carbonamido, PO₃H₂, CO₂H, NO₂,NH₂, alkyl, alkoxy, aryl, amine and acylamine; (iv) at least one of L¹and L² carries at least one substituent selected from sulpho, carboxy,C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH; (v) when L¹ carries a methoxy group A isnot 1,3-diaminophenyl; and (vi) L¹ and L² each independently carries 0to 3 substituents such that at least one of L¹ and L² carries at leastone substituent selected from the group consisting of sulpho andcarboxy.
 6. A compound according to claim 5 wherein L¹ is unsubstitutedphenyl or naphthyl or phenyl or naphthyl carrying a substituent selectedfrom sulpho and carboxy.
 7. A compound according to claim 5 wherein L²is phenyl or naphthyl carrying at least one substituent selected fromsulpho, carboxy, C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH.
 8. A compound accordingto claim 5 wherein L² is phenyl carrying two C₁₋₄-alkoxy-OHsubstituents.
 9. A compound according to claim 5 wherein: A isoptionally substituted; L¹ unsubstituted phenyl or naphthyl or phenyl ornaphthyl carrying a substituent selected from sulpho and carboxy; L² isphenyl or naphthyl carrying at least one substituent selected fromsulpho, carboxy C₁₋₄-alkoxy and C₁₋₄-alkoxy-OH; and m and n are eachindependently 0 or 1 such that m+n is 1 or 2; wherein said optionalsubstituents are selected from OH; SO₃H; CN; carbonamido; PO₃H₂; CO₂H;NO₂; NH₂; unsubstituted C₁₋₄-alkyl or C₁₋₄-alkyl carrying a sulpho,carboxy, phosphato, C₁₋₄-alkoxy, amino or hydroxy group; unsubstitutedC₁₋₄-alkoxy or C₁₋₄-alkoxy carrying a sulpho, carboxy. phosphato,C₁₋₄-alkoxy, C₁₋₄-alkyl, amino or hydroxy group; phenyl or phenylcarrying from 1 to 3 substituents selected from sulpho, carboxy,phosphato, C₁₋₄-alkoxy, amino, hydroxy and N carrying one or twounsubstituted C₁₋₄-alkyl groups or C₁₋₄-alkyl groups carrying a sulpho,carboxy, phosphato, C₁₋₄-alkoxy, amino or hydroxy group; N carrying oneor two unsubstituted C₁₋₄-alkyl groups or substituted C₁₋₄-alkyl groupscarrying a sulpho, carboxy, phosphato, C₁₋₄-alkoxy, amino or hydroxygroup; and C₁₋₄-acylamino.
 10. A tris-azo compound of Formula (1), asshown in claim 5, or a salt thereof wherein: A is pyridonyl carrying atleast one substituent selected from carbonamido and C₁₋₄-alkyl; L¹ isphenyl carrying at least one sulpho substituent; L² is phenyl carryingat least one substituent selected from sulpho, carboxy C₁₋₄-alkoxy andC₁₋₄-alkoxy-OH; and m and n are both
 1. 11. A composition comprising acompound of Formula (1) or salt thereof as defined in claim 1 and a lowmelting point solid or a liquid medium comprising water and an organicsolvent, wherein the compound of Formula (1) is not Formula (3) or asalt thereof:


12. A composition comprising a compound of Formula (1) or a salt thereofand a low melting point solid or a liquid medium comprising water and anorganic solvent, wherein the compound of Formula (1) is as defined inclaim
 6. 13. A composition according to claim 11 or 12 which has aconcentration of less than 500 parts per million of halide ions, whereinparts refer to parts by weight relative to the total weight of thecomposition.
 14. A composition according to claim 11 which has less than50 parts per million of divalent and trivalent metals, wherein partsrefer to parts by weight relative to the total weight of thecomposition.
 15. A paper, an overhead projector slide or a textilematerial printed with a composition according to claim
 11. 16. An inkjet printer cartridge, optionally refillable, comprising one or morechambers and a composition, wherein the composition is present in atleast one of the chambers and the composition is as defined in claim 11.17. A paper, an overhead projector slide or a textile material printedwith a compound according to claim
 5. 18. A paper, an overhead projectorslide or a textile material printed by a process according to claim 1.